This issue of Endocrinology Clinics, authored by experts worldwide, provides essential updates about insulin-like growth factors (IGFs). The physiology is examined, including the latest in what we have learned from animal models as well as humans. The issue also covers IGFs and IGF system in the following: growth disorders; adipogenesis and obesity; muscle function and disease; bone; cancer; cardiac function and disease; normal and diseased kidney; peripheral nervous systems; gastrointestinal diseases; diabetes and metabolism; and IGF-1 central/degenerative diseases.